The exemplary embodiments relate to a method of generating a video reproduction synchronizing signal, a program for generating a video reproduction synchronizing signal, a timing control apparatus, a method of synchronously reproducing a video and an audio, a program for synchronously reproducing a video and an audio, and an apparatus for synchronously reproducing a video and an audio.
When reproduction of a video and an audio are performed, if the video and the audio are not extremely accurately reproduced in synchronization with each other, a viewer may experience deviation of the synchronization as a sense of incongruity. Extremely accurately synchronizing a video and an audio so as not to give such a sense of incongruity or a technique therefore, is called “lip-sync” or “lip-synchronization”, “AV (Audio-Video) synchronization”, and the like.
Since frequencies of clocks used for reproduction of a video and an audio are different, in an ordinary video audio reproduction apparatus, it is necessary to prepare different timers for the video and the audio, and manage resources for the prepared timers, respectively. In the case of such a constitution, there is a problem in that, if there are errors in the respective timers for video reproduction and audio reproduction, errors of reproduction timing for the video and the audio accumulate to make it impossible to maintain the lip-sync.
Thus, as a technique for coping with this problem, there has been proposed a technique for counting the number of output samples of audio data with a counter for audio data output and correcting a timer for video reproduction on the basis of a value of this counting (e.g., see JP-A-2003-339023). According to the technique described in JP-A-2003-339023, since the timer for video reproduction is corrected on the basis of a timer for audio reproduction, it is possible to control the accumulation of errors of reproduction timing for a video and an audio.